通信工程文献翻译——第0层：无位置管理

在早期的广域无线系统中（蜂窝系统的前身），采用人工操作来处理呼叫，用户定位不是由系统来管理的。用户能通过任何基站（BS）建立呼叫，对被呼台的寻址信息要向所有基站发送。这些系统的主要特征是小区半径很大，用户呼叫密度和呼叫率都很低。

小容量蜂窝系统（用几十个基站服务几千个用户）可以也不用位置管理方法、即使当标准允许的情况下。如果用户号码和呼叫率都未达到采用位置管理的要求，那么就没有必要采用位置管理。

这种0层次是再简单不过了：不需要执行位置管理功能（即系统不用追踪用户）。寻找被呼叫的用户需要在整个网络覆盖范围内进行，并在限定的时间内完成。这个方法一般叫做漫溢算法。其一般用于无线寻呼系统，因为这种系统中没有上行链路，移动台也就没有办法把位置信息告知系统。这种方法也用于小型专用的移动通信系统，因为这种系统覆盖地区小，用户也少。

显然，无需确定移动终端位置的主要优点是简单，而且不必安装专门的数据库。当然，这种方法不适合处理大量用户和高的呼入率的大型网络。

第1层：人工登记

人工登记需要用户在收到一个呼叫时调用一个专门的程序来指示其位置。从网络角度来看，这个方法比较容易管理，因为网络只需管理一个存储用户当前位置的指示器。移动台也相对简单，因为它的任务只是限于扫描寻呼信道以检测寻呼信息。这个方法已用于采用无线中继的无绳电话系统（比如法国的Bi-Bop CT2系统）,用户必须遇到新的CT2信标塔时进行重新登记。需要呼叫用户时，网络首先通过用户已经登记过的塔岛发射寻呼信息，如果用户未应答，则再通过邻近的塔发射寻呼信号。

这种方法的主要缺点是需要用户每到一个地区都要进行登记，但是这种低.......

LEVEL 0: NO LOCATION MANAGEMENT

In early wide-area wireless systems (not yet cellular), human operators had to process the calls and the users' location was not managed by the system. A user was able to generate a call through any base station (BS), and paging messages addressed to the called mobiles were transmitted through all BSs. The main characteristics of these systems were very large cells, and low user population and call rates. Small-capacity cellular systems (with a few tens of BSs serving a few thousand users) may also not use a location management method, even when the standard allows it. If subscriber number and calling rates do not require it, the location management method is not activated. This level 0 method is therefore as simple as could be: no location management is realized; the system does not track the mobiles. A search for a called user must therefore be done over the complete radio coverage area and within a limited time. This method is usually referred to as the flooding algorithm. It is used in paging systems because of the lack of an uplink channel allowing a mobile to inform the network of its whereabouts. It is also used in small private mobile networks because of their small coverage areas and user populations. The main advantage of not locating the mobile terminals is obviously simplicity; in ......